how long did it take seurat to paint sunday afternoon
Seurat’s painting was a mirror impression of his own painting, Bathers at Asnières, completed shortly before, in 1884. Whereas the bathers in that earlier painting are doused in light, almost every figure on La Grande Jatte appears to be cast in shadow, either under trees or an umbrella, or from another person. For Parisians, Sunday was the day to escape the heat of the city and head for the shade of the trees and the cool breezes that came off the river. And at first glance, the viewer sees many different people relaxing in a park by the river. On the right, a fashionable couple, the woman with the sunshade and the man in his top hat, are on a stroll. On the left, another woman who is also well dressed extends her fishing pole over the water. There is a small man with the black hat and thin cane looking at the river, and a white dog with a brown head, a woman knitting, a man playing a horn, two soldiers standing at attention as the musician plays, and a woman hunched under an orange umbrella. Seurat also painted a man with a pipe, a woman under a parasol in a boat filled with rowers, and a couple admiring their infant child. 
In 1879 Georges Seurat enlisted as a soldier in the French army and was back home by 1880. Later, he ran a small painter’s studio in Paris, and in 1883 showed his work publicly for the first time. The following year, Seurat began to work on La Grande Jatte and exhibited the painting in the spring of 1886 with the Impressionists.  With La Grande Jatte, Seurat was immediately acknowledged as the leader of a new and rebellious form of Impressionism called Neo-Impressionism. 
Though the subjects of A Sunday Afternoon on the Island of La Grande Jatte are rendered in an unrealistic and almost minimalist style, Seurat opted to place them in a range of positions (“of some we see the backs, some we see full-face, some in profile, some are seated at right angles, some are stretched out horizontally, some are standing up straight,” art critic Félix Fénéon remarked in 1886). This decision adds a sense of realism to the otherwise stylized depiction and helps draws the viewer into the receding scenery.
Another optical trick evident in this painting is Seurat’s inclusion of an innovative painted “frame.” According to the Art Institute of Chicago, this Pointillist border is supposed to “make the experience of the painting even more intense” by adding even more colors, tones, and a textures to the composition.
Georges Seurat, Sunday at La Grand Jatte, 1884, Art Institute of Chicago, detail
Known as croquetons—literally ‘sketchettes’—Seurat’s studies were all made on small wooden panels. Extraordinarily proud of them, he hung many in his studio. He also exhibited them regularly, demonstrating the significance he felt they had in his oeuvre. Seurat called the panels his ‘constant joy’.
This Seurat’s painting was actually a mirror impression of his own earlier painting executed in the same year, Bathers at Asnières  . Whereas the figures in the earlier painting are doused in light, everyone portrayed in A Sunday Afternoon on the Island of La Grande Jatte appears to be cast in shadow, either under trees or an umbrella, or from another person.
In terms of perspective, most of the figures’ view is focused on the river to the left of the image. Despite the fact the river comprises only a small part of the painting, the activities in this segment draw the viewer’s gaze. The figures at the front appear to be very close to the viewer – the woman walking a monkey and the man beside her are the biggest figures in A Sunday Afternoon On The Island Of La Grande Jatte and their size balances this work of immense proportions.
In his autobiography, Dalí explained that his second expulsion was the result of him refusing to submit to an oral exam, telling them, “I am infinitely more intelligent than these three professors, and I therefore refuse to be examined by them. I know this subject much too well.” This marked the final straw for his academic career.
Not just Seurat’s most popular piece, but also his biggest, A Sunday on La Grande Jatte —1884 measures in at 81 3/4 inches by 121 1/4 inches, or about 7 feet by 10 feet. Its large size makes its every inch flush with tiny dots of color all the more remarkable.